feat: Setup React Frontend (Issue #1)

- Initialize Vite + React + TypeScript project
- Install dependencies (React Router, Zustand, Axios, Tailwind CSS)
- Configure Tailwind CSS and PostCSS
- Create basic folder structure
- Setup ESLint and Prettier
- Create placeholder pages (Login, Dashboard, Logs, Alerts, etc.)
- Create Layout and ProtectedRoute components
- Add TypeScript types

Closes #1

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

frontend/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+}